Abstract

Azobenzene dyes have large refractive index near their main resonance, but the poor figure of merit (FOM) limits their potential for all-optical applications. To improve this situation, disperse red 1 (DR1) molecules were dispersed in a sol-gel germanium/Ormosil organic-inorganichybrid matrix. Z-scan measurement results showed a good compatibility between the dopant and the matrix, and also, an improved FOM was obtained as compared to the DR1/polymer films reported previously. To demonstrate the all-optical signal processing effect, a cw Nd:YAG laser emitting at 532 nm and a He-Ne laser emitting at 632.8 nm were used as pump and probe beams, respectively. DR1 acts as an initiator of the photo-induced transient holographic grating, which is attributed to the trans-cis-trans photoisomerization. Thus, a three inputs AND all-optical logic gate was achieved by using choppers with different frequencies. The detailed mechanism of operation is discussed. These results indicate that the DR1 doped germanium/Ormosil organic-inorganichybridfilm with an improved FOM has a great potential in all-optical devices around its main resonance.

This work was supported by the National Natural Science Foundation of China under Grant No. 61078058, the Research Fund for the Doctoral Program of Higher Education of China under Grant No. 20120201130004, the Science and Technology Developing Project of Shaanxi Province under Grant No. 2015KW-001, and partially by the National Natural Science Foundation of China Major Research Plan on Nanomanufacturing under Grant No. 91323303, and the 111 Project of China (B14040).